Storage space, or rather the lack of it, is a big problem in many areas, such as computer operations where it is desired to store large numbers of tapes or tape cartridges containing computer data for frequent retrieval or for archival storage. Similar problems exist in other contexts, such as libraries, file rooms, and the like. Floor space is usually at a premium and the cost per square foot can be quite expensive. Normal business growth requires either more space for storage or more efficient use of existing space.
Prior attempts to solve storage problems have been only partially successful. One approach, as shown in U.S. Pat. Nos. 4,600,107 and 4,688,682, has been to increase the storage density on fixed shelves by doubling the number of articles stored on the shelves. This approach seeks to eliminate "dead space" between shelves. However, to accommodate growth, more storage racks, and therefore more floor space, are required.
Another approach seeks to increase storage capacity using a combination of fixed and sliding storage units. In such systems, a bank of fixed units is combined with one or more sliding units in front of the fixed units. However, while increasing storage capacity, sliding unit designs restrict access to the fixed units. Access to the fixed units can be restricted by up to 80 percent. In addition, with sliding unit installations, an operator is required to manually shift several hundred pounds of stored material contained in a sliding unit in order to gain access to the fixed units behind the sliding units. This may require as much as 1200 pounds of effort. In addition, sliding units move on rollers in tracks, and often malfunction, delaying access to materials stored in the fixed units.
The present invention provides an innovative solution to the problem of increasing storage density without excessively restricting access to stored materials and while maximizing ease and speed of operation. The present invention concentrates the maximum amount of storage in the minimum amount of floor space. On average, the invention enables increases in storage capacity of up to 40 percent or more. The invention has a minimum negative impact on productivity, because it provides a user with fulltime access to materials stored in inner compartments. Sliding unit designs limit access to 20 percent of materials stored in the inner compartments. Unlike sliding unit designs, the invention is very mobile, leading to significant savings in labor expense during installation or reorganization activities by eliminating the need for assembly or leveling. Sliding unit designs require extensive and timely consuming installation, assembly and leveling operations, and require disassembly if they need to be relocated. The present invention is highly mobile and can be quickly and simply installed or relocated as required.
These and other objects and advantages of the invention will become apparent from the accompanying description of the invention.